爬上来问一道题prep语法笔记237. (GWD-8-Q16) (GWD-13-15)

cuijinshufe

237.(GWD-8-Q16) (GWD-13-15)Concerns about public health led to the construction between 1876 and 1904 of three separate sewer systems to serve metropolitan Boston
.
A.Concerns about public health led to the construction between 1876 and 1904 of three separate sewer systems to serve

B.Concerns about public health have led to the construction of three separate sewer systems between 1876 and 1904 to serve

C.Concerns about public health have led between 1876 and 1904 to the construction of three separate sewer systems for serving

D.There were concerns about public health leading to the construction between 1876 and 1904 of three separate sewer systems serving(A)

E.There were concerns leading between 1876 and 1904 to the construction of three separate sewer systems for serving
答案是a，我怎么觉得a里面读不通呢？

我这么想的
结构分析的对吗？
Concerns （about public health） led to the construction （between 1876 and 1904 of three separate sewer systems） to serve，怎么觉得不通呢？
求牛人指点啊

AlohaDJ

应该是Concerns （about public health） led to the construction （between 1876 and 1904) of three separate sewer systems (to serve)...

cuijinshufe

感谢！另外问一句，最后那个to serve在这里 是什么作用？是什么成分呢？

AlohaDJ

不定式作后置定语修饰它紧邻的systems~

cuijinshufe

学到啦，谢谢！